1. Field of Invention
The present invention relates to folding bicycles and more particularly to such a folding bicycle with improved characteristics (e.g., shock absorbing device mounted under seat tube and two auxiliary rear wheels for increasing riding balance).
2. Related Art
A conventional folding bicycle is shown in FIGS. 1 and 2 and comprises a handle 80 including a pair of handlebars 81 on a top, and a front wheel 82 on a bottom; a seat 83 including a seat tube 831 extended downward; a first crossbar 84 having a front end pivotably connected to a lower portion of the handle 80 proximate the front wheel 82 and a rear end fixedly connected to an intermediate portion of the seat tube 831; and a pair of second crossbars 85 having two front ends pivotably connected to an intermediate portion of the handle 80 and two rear ends fixedly connected to both ends of an hub of a rear wheel 86 in which the first crossbar 84 passes an intermediate portion of the second crossbars 85 and is pivotably connected thereto.
There is a small distance between bottom of the seat tube 831 and the second crossbars 85. Thus, a portion of the first crossbar 84 proximate the joining point of itself and the seat tube 831 may deflect an angle θ when a person sits on the seat 83. The structural strength of the first crossbar 84 may decrease gradually as riding times increase. Thus, it is highly possible that the first crossbar 84 may break after a period time of use. Moreover, there is no support to either side of the bicycle. Thus, riding safety is not sufficient. This is particularly true for a young rider (e.g., child). Thus, the need for improvement still exists.